Isopropyl alcohol construction

A modified Hahn condenser, a form of partial condenser, is illustrated in Fig. VI, 12, 1 it is best constructed of Pyrex glass. The dimensions given are only approximate and may be varied slightly. The inside clearance should be approximately 0-3 cm. a water jacket should be fitted over the central portion of the side arm by moans of rubber stoppers. Alternatively, the side arm may have a length of about 10 cm. and a condenser fitted to this in the usual manner. An approximately 1 cm. layer of absolute alcohol is placed in the inner condensing tube and the top of the tube is connected to a reflux condenser. The outside of the condenser below the side arm should be insulated with asbestos cloth or paper. The refluxing mixture boils the ethyl alcohol in the inner tube, most of the isopropyl alcohol is returned to the flask and the acetone distils over. 

Fig. 10.2 Effect of buffer composition on the ESI-FTICR-MS spectrum of a 27mer RNA construct representing the 16S A-site. The spectrum in (a) was acquired from a solution comprised of 33% isopropyl alcohol and 25 mM piperidine/imidazole with an approximate pH of 8.5. The spectrum in (b) was acquired from a solution containing the...

More elaborate means have been described for removing the acetone by distillation with relatively little isopropyl alcohol. These include various columns such as a Vigreux13 or a modified Widmer column.10 They are to be recommended when the aldehyde or ketone boils Within 50° of isopropyl alcohol, but are unnecessary under other circumstances. A reflux condenser maintained at constant temperature by boiling methanol has been suggested.6 More convenient than this is the simple but effective partial condenser designed by Hahn.49 An easily constructed modification is illustrated in Fig. 3 (adapted from Organic Syntheses).60 The partial condenser is attached directly to the round-bottomed flask, and ethanol is placed in the inner condensing tube. The... 

The most important consideration in the selection of the filter is the compatibility of the filter materials of construction with the solvent. The solvents used in pharmaceutical processes can be very aggressive. They include acetone, methanol, ethanol, isopropyl alcohol (IPA), acetonitrile, dimethyl acetamide, dimethyl formamide (DMF), ethyl acetate, tet-rahydrofurane (THF), methyl isobutyl ketone (MIBK), and methyl ethyl ketone (MEK). Filters with PTFE membranes and polypropylene supports are used in most applications. 

Schemes 5.2c and 5.2d show the construction of two other simple alcohols. One is isopropyl alcohol, which is used in cleaning liquids for television, computer, and cellphone screens, and also for massages. The second alcohol is ethylene glycol, which is used as an antifreeze agent. Many other alcohols, such as menthol, geraniol, and methyl sahcylate, are produced by plants and cause muscle relaxation, antiinflammatory effects, and so on. Please do not get intimidated by all the names. We note them so you could refer to them in case you need, but not every name must be memorized.

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